Art wrote:
"Most hams who strive for maximum radiation that is horizontally
polarized place the radiator parallel to the earth`s surface."

Reflection from the ionosphere nakes unpredictable changes in
polarization. Nevertheless, the angle of arrival equals the angle of
reflection at the ionosphere. Experience shows best results on a
transmission path happen when the antennas at both ends of the path are
complimentary. See E.A. Laport, "Radio Antenna Engineering" page 215,
"High Frequency Antennas".

Best regards, Richard Harrison, KB5WZI